Onboarding device has started returning "registerCertificate" errors.

[Chris Chubb]

We use the https://api.nrfcloud.com/v1#tag/IP-Devices/operation/OnboardDevices endpoint to create and onboard new devices. 

Recently, with no changes to code or certificates on our end the system has started returning `registerCertificate` errors for the batch results of certain requests. 

Is there a way to determine which certificate is causing the error and what the internal error is? There is a global root certificate, the new client certificate that is generated and the signing certificate on record at nrfcloud. 

Only 3 devices have thrown errors of this type in the last 3 days, out of approximately 90 provisioning requests. 

[Grayson Fleming]

Hi Chris, we are looking into this. To help us Identify exactly what might be happening with this error would you mind providing us with a little more information?

- were the first of these errors showing up in the last 3 days or has it been happening for a longer period?
- which modality is being used for this request? (For the `certPem` parameter, are you using an ES256 X.509 certificate or are you entering a public key in PEM format) based on your question it appears you are using an X.509, is this a correct assumption?
- is there any difference in the bulk requests for the failed devices (other than the certificate or public key provided)?
- any chance you could provide the full error? is it consistent between devices?